This was inspired by Jessman's post in the nuke power thread:

"Solar and wind power need to be explored further to see if we can eliminate the problems with cloudy or windless days"

On a serious note, what if a whole bunch of solar stations 'round the world were connected in parallel? That way if one region were in darkness or under cloudy weather, as long as it is connected into the power grid, it will get power from another station somewhere in the world. I'm talking about a lot of stations, not just one or two per time zone, like hundreds or thousands connected in a global project.

At sealevel, 1000Watts can be collected per meter squared. Someone in the other thread mentioned a local nuke plant generated 400MW, then 400,000 m² is needed as an equivalent. That's a 600-m square or 9 acres. I think developing the parallel connection between power plants should generate more than enough for the world on any given day -- provided there was enough to go around.

Another good idea, but building a completely new power grid would take decades and cost billions if not more.

And how long could they last and would you get your money's worth?

It would last forever, just about, and does not pollute.


The only issue I see is political if an country decided to cut itselfoff the grid, like an embargo; I think they would be hurting themselves more. Like when Saddam tried to restart another oil embargo and no one else followed suite, that was funny.

[Edited 2004-01-20 02:27:08]

How about this:

Build three massive solar arrays in geosynchronous orbit over the earth, then build massive microwave recievers on the ground directly below them. Transmit the energy via microwave from the arrays to the recievers, and you have an infinite source of solar energy.

Just hope that they have good aim, or it would suck to live next to the recievers.

DLKAPA

Ah yes mircowave, I remember that one from Sim City 2000. It sounds like a pretty good idea. Is the government or power companies exploxing this option?

Nice try. But two flaws...

1. If you park them in Geosynchronous orbit, they won't stay "locked" on the sun, but will stay locked over some palce on the Earth.

2. You cannot transmit that kind of energy via Microwave.

If possible, it would (could) be efficient.

Question is, if the energy investment for putting the satellites into orbit could ever be recovered economically by the improved efficiency vs. ground-based arrays (but again reduced by the losses of the microwave transport).

Wire-based power distribution, on the other hand, has its own efficiency problems over distances of thousands of kilometers...

Wire based power distribution is hampered by resistance. The farther away the power needs to be delivered, The more resistance there is, the more loss there is. That is why power stations are built close to the load. If there was a way to eliminate that resistance/loss, you could build 'super generators' and distribute further.

Lehpron, those numbers are a bit off.

The sun's energy hitting the earth is equivalent to about 1000 watts per square meter. However, we can't harness nearly that much.

Standard solar panels may (and this is a very generous estimate) be able to collect 200 Watts (though some may have the potential to get better performance still). On a cloudy day, this can drop below 40 Watts. Figuring on a very generous 250 watt average per square meter, you need 4,000 square meters per megawatt, or 1,600,000 square meters to equal a typical nuclear reactor (more if there happens to be a cloud or two).

That means you need a clear sky and 400 acres of solar panels to generate 400MW.

If you figure that solar panels, bought in bulk, cost $400 per square meter (looking at some rooftop models, square meter cost was between $600 and $1000), you can expect to spend $640,000,000. $640 million for just for panels. Add the cost of all the structural supports for the panels, machinery that turns them to an optimum position, the cost of the land, etc... your easily talking a billion dollars.

And the above is an extremely generous estimate. Solar I, which operated in the 1980s, produced 10MW and took up 100 acres. It used a different technology (directed the solar energy with mirrors to power a furnace) that was much cheaper, but it still was not financially viable.

SEGS IX, the largest solar plant in the world, generates 80MW and takes up 1,000 acres... at that ratio, it would take 5,000 acres to produce the power of one nuclear plant.

Conservatively, a 400 MW power plant would cost about $3,000 per kilowatt (according to a study done investigating the SEGS program and its applicability to Hawaii... the Hawaii SEGS would of cost 4,500 per kilowatt because of land costs.) This puts the cost of a 400 megawatt array at 1.2 billion.

In 2004, one estimate put US power demand at 709 Gigawatts. to produce 10% of that energy (70.9GW) with solar power, it would cost a staggering 212.7 billion dollars... and that assumes that the 177,250 acres needed all cost $1,000 each and have no cloud cover 300 days or more per year. And that’s 10%. For 100%, you'd need an area of land at $1,000 an acre, and sun at least 300 days a year, 10% larger than the state of Delaware (just shy of a 2,800 square mile, or 1772162 acre power plant), costing 2.127 trillion dollars.

Now we can talk about Europe  .

Solar power is a great idea, but it is not yet feasible. Perhaps new technology will be developed that will allow us to inexpensively gather 90% of the suns energy, instead of less than 30%, but until then, widespread solar use will remain a dream.

"one estimate put US power demand at 709 Gigawatts"

that is a big part of the problem. and the sad thing is, even though the u.s. already have an utopical energy consumption per captia compared to equally developed countries, it still keeps rising faster then any other per captia consumption.

That idea with the satellite collectors, I heard it was initially something the Soviets thought of when they used to own the northern most region, north of the arctic circle; they would have placed a microwave energy reciever station there, but there was some concern about wildlife flying into the beam and, uh popping, that did not go over very well with some folks in the US that considered the idea.

Anyway, microwave dishes "can in principle" transmit energy that can be converted into electricity and vice versa, although IMO, it would make more sense to put a giant mirror reflector in space and beam it to one of the poles with 6 months of straight solar energy.

In terms of resistance in wires, how about fiber-optic cables? Yeah they are expensive, but there has to be some advantage if people are using them now.

If the losses are really that bad running a cable say under the ocean to connect countries, maybe use a jumpstation that maintains power levels by using tidal energy from the ocean.

I donno, I'm just spitting ideas out now.  

BTW JeffM, when something is geo-whatever with the earth, yeah it is locked to earth but it is also locked to earth with respect to the suns frame of reference as well. think of the orbiting object as chasing the earth while it orbits the sun -- it would always be in the sun.

Thou I see a cooling issue despite the cold-dead of space. Like I was watching the Discovery channel about repairing satellites, one side could be +400F and the other could be -400F, is that enough of a torturous experience? Even satellites get to float in the shade of the Earth for a while.

"The sun's energy hitting the earth is equivalent to about 1000 watts per square meter. However, we can't harness nearly that much"

Actually I got those number from my physics book, by Seraway called 'Physics for Engineers and Scientists, in chapter 34, it states the total from the sun being at 10KW/m², but 90% of it gets lost due to our atmosphere. But then I did not consider a lot of things, like the efficiency of photovoltaic cells. Solar heating is at least twice as efficient. My though was just too connect a world of cells in parallel instead of "each his own", the overall cost over time would benefit everyone even though it may cost bank now.

But 709 gigawatts...how a 'bout geo thermal? Or everyone who drives a car can attach a trailer with generators hooked up to its wheels and they can generate their own power as they drive in the day and either choose to drive that energy back into the system or use it themselves.

Or we can cancel a couple of bad reality shows...  

Lehpron: Anyway, microwave dishes "can in principle" transmit energy that can be converted into electricity and vice versa, although IMO, it would make more sense to put a giant mirror reflector in space and beam it to one of the poles with 6 months of straight solar energy.

Either you´d get a major global warming / sea level problem as a result - or a black scorchmark somewhere in Poland.  


Lehpron: In terms of resistance in wires, how about fiber-optic cables? Yeah they are expensive, but there has to be some advantage if people are using them now.

Wires have another problematic property for power distribution: In addition to the resistive loss as JeffM already said, every wire carrying an alternating current signal will also act as an antenna which will turn part (or all) of the energy into electromagnetic radiation - and will also feed electromagnetic energy from solar storms back into the systen (but not in a well-usable form). There´s that old story of that new, very long power line in Africa that basically "lost" all the power that was pumped into it - it was a near-perfect antenna for the grid frequency!

Fiber optics, on the other hand, have no advantage in power transmission I´d know of. Quite the opposite, in fact (optical connections usually operate in very low power mode). Only the data is regenerated at the receiver; The energy is absorbed and converted to heat (lost). The primary benefits of optical cabling are:

a) keeping the devices´ electical potentials separated
b) reducing electromagnetic interference both to and from the signals
c) allowing for very high data rates


Lehpron: BTW JeffM, when something is geo-whatever with the earth, yeah it is locked to earth but it is also locked to earth with respect to the suns frame of reference as well.

No... A geostationary satellite will rotate at the same rate as the earth and consequently would have to readjust its solar panels even during the time it wasn´t obscured by the earth´s shadow.


Lehpron: think of the orbiting object as chasing the earth while it orbits the sun -- it would always be in the sun.

Not possible with a geostationary satellite. Even a polar orbit (necessary to stay in the sun) would have to be re-adjusted as the earth follows its orbit around the sun.


Lehpron: Solar heating is at least twice as efficient.

Yes. And efficiency gains can provide another large contribution.


Lehpron: My though was just too connect a world of cells in parallel instead of "each his own", the overall cost over time would benefit everyone even though it may cost bank now.

With a lossless ring connection (supraconductors), there would be a chance, even if the whole thing was economically feasible. But then, you´d still have to distribute the power everywhere...


Lehpron: Or we can cancel a couple of bad reality shows...

That is a brilliant idea!  

Thanks Klaus, I thought I was right on the satellite thing.  

Well, we could always stick one out at a Lagrange (sp?) point and see how it works out  

Wire based power distribution is hampered by resistance. The farther away the power needs to be delivered, The more resistance there is, the more loss there is. That is why power stations are built close to the load. If there was a way to eliminate that resistance/loss, you could build 'super generators' and distribute further.

Hence, higher transmission voltages.
(In other words, ensuring that the stepdown transformer at the far end appears to have a much higher resistance than the transmission line)

In terms of resistance in wires, how about fiber-optic cables? Yeah they are expensive, but there has to be some advantage if people are using them now.

Fibre-optic cables transmit light, not electricity. Light has certain advantages for signalling purposes, but it's not practical as a means of power transmission, for various boring optical & optoelectronic reasons. Would you power your PC with a cat5 cable?

BTW JeffM, when something is geo-whatever with the earth, yeah it is locked to earth but it is also locked to earth with respect to the suns frame of reference as well. think of the orbiting object as chasing the earth while it orbits the sun -- it would always be in the sun.

You might have noticed that most parts of the earth regularly alternate between light and dark, twice per day.  
How can any particular location consistently have a line-of-sight to the sun, and be above a part of the earth's that doesn't have a line-of-sight to the sun? (With the exception of the poles, &c)

90% of it gets lost due to our atmosphere.

No; considerably less than that. Surface reflection/radiation accounts for a considerable fraction too. However, this isn't really relevant  

This is the micro-whatever principle that I am basing my idea on. When you transmit audio from a wireless microphone to a reciever, you are transmitting at a certain frequency a very small amout of electromagnetic energy in a non-directional pattern, picked up by a reciever, and converted to electricity.

It is however possible to also transmit audio through directed lazer beams. Again, you are transmitting audio inside a very small amount of electromagnetic radiation.

At the reciever end, it converts the lazer energy from an airborne electromagnetic signal to a wire-borne electric signal, which can be fed to whatever you want it to go to.

In the case of orbiting solar arrays, the signal would be transmitted in a highly directed lazer beam, with much, much, much more electromagnetic energy. It would mean that the reciever on the ground would need to be able to withstand very high amounts of electromagnetic energy.

the reciever, as stated above, would convert the signal from airborne energy to wire-borne energy.

It all works in theory.

DLKAPA

Your theory is wrong Eric. What you transmit is information via frequency, not energy itself. You transmit the audio information (coded)via radio frequency, IR, etc, then decode it and with the aid of an additional power source, turn it back into magnetic pulses to the driver (magnet) of a speaker.

Jeff

If there was no energy used in transmission, then how would you transmit?

Why do you think the KOA radio tower out here holds a 50,000 Watt transmitter? Why would they spend that much money on wattage if there was no energy used?

DLKAPA

What are you talking about? Of course it takes energy to transmit data. It's just that your using it not sending it.

Use KOA as the example...50,000 watts, used to amplitude modulation only... and how far does it reach?

At night I have been able to pick up KOA from as far away as Missouri.

And All I am saying is that you just amplify the energy at the transmitter in space, instead of a 50,000 watt transmitter, like KOA has, it would be much higher. You don't try to send electricity through air, that would be stupid. You just amplify the carrier wave, were talking into the Gigawatt range. Taking the KOA transmitter as an example, take a smal LED and wire it into a 1/4" or 1/8" monaural plug. Then, plug that into your stereo headphone jack. What will happen? the louder you turn up the volume, the brighter the LED gets.

You have just turned an Electromagnetic signal into usable energy. Now amplify that. When the reciever gets that Gigawatt signal, then the reciever converts it to electricity. Run it through wires to wherever it needs to go.

And best of all, the only limit on the power you can recieve is how powerful the signal is. You could go even higher than a Gigawatt, possibly into the terrawatt range.

DLKAPA

[Edited 2004-01-22 06:08:22]

You have absolutely no idea what your talking about.
zilch.

Done with this one.

The problem is in the losses you´d encounter. Of course it could work in principle; But any gains at the generator would be more than nullified by transmission loss (and the equally obvious dangers of an error in antenna targeting).

Almost all "good ideas" fail because they´re inefficient/impractical. The small rest is what our civilization is built upon.

[Edited 2004-01-22 11:16:58]

Images of a hundred foot Tesla Coil and melting generators spring to mind....

The answer lies in harnessing the rotation of the Earth and using it as a giant generator. In the meantime, we can carpet Cuba and pay the locals to shuffle their feet on it all day.

People get upset about 709 GW demand for the U.S, but think of what it will be in 100 years, when the population has gone up 2 or 3 times, and as fossil fuels will be gone or almost gone, all vehicles, heating systems etc have gone electric. I'd say we would be on the 5000 GW range, guys.

Let's say now that in 100 years, we have developed solar panels that manage to convert 90% of the energy into DC. 5,000,000,000,000 Watts divided by 900W/m2 = 5,556 million m2 = 5,556 square kilometers, an area approximately 50 miles long by 50 miles wide. Pretty big expanse of land. Now what happens when theirs a good hailstorm going accross the country?

The final solution to the energy proble is fusion energy. The sooner we start investing serious money into the R&D for fusion, the better. When fusion reactors are online with cheap energy that releases no harmful polutants, we won't really care how many GW we need.

Charles

The answer lies in harnessing the rotation of the Earth and using it as a giant generator.

Harnessing the rotation of the earth in relation to what? Where would you put your machinery, and how would you link it to non-rotating empty space?

Meanwhile, we do have tidal power generation.

Harnessing the rotation of the earth in relation to what? Where would you put your machinery, and how would you link it to non-rotating empty space?

Let the engineers figure that out if you can't. Start with that big clock and go from there.  

You could try something coriolis-based, perhaps. However, that would require some very large masses moving around to get any appreciable effect.
(wind turbines, anyone?   )

JetService: In the meantime, we can carpet Cuba and pay the locals to shuffle their feet on it all day.

That is by far the most inventive and entertaining solution of the problem!    

"wind turbines, anyone"

sssshhh, dude be quiet! The animal activists will start crying now that you reminded them of all the birds that die after flying into fans, and claim it is our fault.   Someone should let them know how many 'doves' cry when they die...

Speak of silly ideas, how about we stick a fan against a black hole, then maybe it will run forever and the space activists will cry if meteors go into it.

I'm sure they perfer those poor meteors to slam into Earth instead of a BH cuz at least they know where to put the flowers.


Ooh, 'notha silly idea: how bout we attach a large magnet on on techtonic plate and attach a giant solenoid coil onto another and while one plate moves, it generates power.

Or we could just attach a giant sail onto Earth's axies and catch solar wind to spin a giant...space thing that spins...i donno.

I still think that solar chain is a good idea.

BTW, not all photovoltaic cells are made with glass, Cfalk, some are even bendable. Look into them sometime.

Solar panels don't last forever, though. I believe generally they're good for about 30 years, then by that time it's more economical to replace them due to lower output. This is for the rigid silicon panels, not those newer flexible ones. They might have less life.

The fan would be sucked into the black hole and broken down to its basic elements.

DLKAPA